Module: SAGA Wetness Index
(c) 2001 by J.Boehner, O.Conrad
Menu: Terrain Analysis > Hydrology > Catchment Area
Description
The 'SAGA Wetness Index' is, as the name says, similar to the 'Topographic Wetness Index' (TWI), but it is based on a modified catchment area calculation ('Modified Catchment Area'), which does not think of the flow as very thin film. As result it predicts for cells situated in valley floors with a small vertical distance to a channel a more realistic, higher potential soil moisture compared to the standard TWI calculation.

References
- Boehner, J., Koethe, R. Conrad, O., Gross, J., Ringeler, A., Selige, T. (2002): Soil Regionalisation by Means of Terrain Analysis and Process Parameterisation. In: Micheli, E., Nachtergaele, F., Montanarella, L. [Ed.]: Soil Classification 2001. European Soil Bureau, Research Report No. 7, EUR 20398 EN, Luxembourg. pp.213-222.
Parameters
NameTypeIdentifierDescriptionConstraints
Input
Elevation Grid (input)DEM
Output
Catchment areaGrid (output)C
Catchment slopeGrid (output)GN
Modified catchment areaGrid (output)CS
Wetness indexGrid (output)SB
Options
tFloating pointTMinimum: 0.000000